Subway travelers have been able to used cellphones in the C, E line station at Eighth Avenue and 23rd Street since September. Cell service is scheduled for 30 more stations this year.

Cellphone service will arrive at 30 additional subway stations in 2012, including Times Square and Rockefeller Center, broadening access to include much of Midtown, the firm conducting the improvements said this week.

Transit Wireless, which launched cell service in six stations on 14th and 23rd Streets in September, is working to extend cellphone access to the 30 new stations this summer. Construction is slated to begin in April, a spokesman said.

Among the stations scheduled to be wired for cell service this year are those at Times Square, Rockefeller Center, Columbus Circle and stations along 96th Street. A full list of the new locations is below.

The stations would come online in groups of five or six at a time, beginning in July or August, said Patrick Smith, spokesman for Transit Wireless.

Transit Wireless has negotiated deals with AT&T and T-Mobile to provide cell coverage in the subways, and negotiations with other wireless carriers for access to its underground system is ongoing, the company said.

The company also plans to announce the launch of free wireless Internet access in six subway stations within the next several weeks, said Smith. The wi-fi access would be free to subway passengers, and paid for through a sponsorship arrangement still under negotiation.

The MTA has previously estimated the cost of wiring all 271 subway stations in the transit system at roughly $200 million, a cost being borne entirely by Transit Wireless. Transit Wireless and MTA will share proceeds of the company’s contracts with wireless carriers, MTA officials have said, with a minimum annual payment to the transit system of $3.3 million once the cellphone network is complete.

“Bringing wireless service into our underground subway system reinforces the MTA’s effort to use technology to improve customer convenience that allows them to stay in touch with friends, relatives and business contacts,” said Kevin Ortiz, a spokesman for the MTA. “And by having access to real-time service status updates while underground, riders can better navigate the system.”

Meanwhile, the MTA announced the winners of its App Quest contest, in which software developers built applications to display subway data and schedules on smart phones. The winning app, called EmbarkNYC, features GPS navigation, street and subway system maps, and a trip planning feature that doesn’t require a cell phone signal to be operational.